Occurs in 15% aged >65Y, increasing incidence with age in men only. Causes include:
- Sphincter weakness (following childbirth/surgery);
- Anal/rectal pathology e.g. fistulae, Crohn’s, proctitis;
- Neurological disease (chorda equine, pudendal nerve);
- Dementia and unconsciousness;
- Diarrhoea (infective or due to malabsorption);
- Constipation (common in the elderly, diabetes, hypothyroid);
- Drugs e.g. antibiotics, muscle relaxants, PPIs, metformin.
- DRE/PE – assess sphincter function and rule out impaction. Check perianal sensation to rule out neurological cause.